1. Field of the Invention
The present invention relates to fuel metering and control systems and more particularly pertains to a new fuel metering system for selectively controlling the rack pressure and the volume of fuel available to a diesel engine.
2. Description of the Prior Art
The use of fuel metering and control systems is known in the prior art. More specifically, fuel metering and control systems heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art fuel metering and control systems include U.S. Pat. No. 5,448,882 to Dyer et al. The Dyer et al. patent discloses a fuel metering system that independently meters fuel flow to a first and a second set of pilot fuel nozzles, and to a set of main fuel nozzles of a gas turbine engine.
U.S. Pat. No. 5,305,714 to Sekiguchi et al. discloses a fuel supply system for a hydrogen gas engine.
It can then be appreciated that there exists a need for a metering system that selectively controls the rack pressure and the volume of fuel available to a diesel engine. This is particularly desirable in reduced load situations. To achieve this the metering system generally comprises a fuel inlet line in fluid communication with a fuel pump outlet line for receiving fuel flowing from the fuel pump, a metering valve coupled in fluid communication with the fuel inlet line, the metering valve having a means for controlling the flow of fuel therethrough, the metering valve being coupled in fluid communication with a return line for receiving the metered fuel flowing through the metering valve, and a solenoid valve coupled in fluid communication with the metering valve and the fuel inlet line, the solenoid valve being operable to open and close fuel flow through the metering valve.